The Old Town canoe with serial number 88511 is an 18 foot long, CS (Common Sense or middle) grade, HW (Heavy Water) model with red western cedar planking, open spruce gunwales, birch decks, birch thwarts, birch seats, a keel, a floor rack, sponsons, and a brass painter ring. It was built between October, 1925 and April, 1926. The original exterior paint color was gray with "W. B. C. C." lettered on the right bow and left stern. It shipped on May 14th, 1926 to Rye, New York. A scan of this build record can be found by following the link at the attached thumbnail image below.

It is also possible that you could have another number or manufacturer if this description doesn't match the canoe. You may want to take a closer look at that serial number and confirm the overall length of the canoe in a straight line. The 16 on the end of the number you provided indicates that you really have a 16 foot long canoe. The information at http://www.wcha.org/forums/index.php?threads/791/ may help. Some pictures would also be good. Feel free to reply if you have any other questions.